What was found
PASSING FL 340, CLIMBING TO FL 350, THE AIR CONDITIONING WENT TO A HIGH FLOW VOLUME. ACFT PRESS IS NORMAL. TURNING OFF RECIRC FANS HAS NO EFFECT ON THE VOLUME. VERY NOTICABLE IN FLIGHT DECK AND FIRST CLASS LAV NOT AS NOTICABLE IN REAR OF ACFT. VOLUME RETURNED TO NORMAL AFTER APPROX 15 MIN IN CRUISE. ACFT GROUNDED. ACCOMPLISHED EEC AND PSE FAULT HISTORY INQUIRY AND NO FAULTS LOGGED. PACK/ZONE BITE TEST, NO FAULTS FOUND. PERFORMED PACK FLOW CONTROL VALVE (LT AND RT) OP TEST MM 21-51-00-700-802, CHECKED GOOD. COMPLIED WITH EA 800-21EA-10692, NO DEFECTS NOTED. GROUND VERIFICATION CHECKS GOOD. NO DEFECTS NOTED AT THIS TIME, NO HISTORY.